The repair of inguinal hernias is one of the most commonly performed surgical procedures. Various prosthetic materials, typically porous to allow for tissue ingrowth, have been provided in a variety of combinations, forms and shapes. Surgical mesh, typically of polypropylene, has been commonly used, in some instances having been rolled up into a cylindrical shape and inserted into the defect as a plug. To reduce the tendency to migrate, these plugs are sometimes affixed at one end to the center of a sheet of material. The sheet is used to overlap the defect and for attachment to the adjacent tissue to reduce the likelihood of migration of the device; see, for example, U.S. Pat. No. 5,116,357 to Eberbach and U.S. Pat. No. 5,147,374 to Fernandez. These sheet-and-plug devices lend themselves to laparoscopic repair as they may be inserted via a trocar wherein, after insertion, the edges of the sheet may be fastened to the tissue adjacent the defect.
Hernia repair plug devices have been refined into a variety of shapes. One such commercially available device is the PerFix® Plug from C.R. Bard, Inc. (Murray Hill N.J.), described in U.S. Pat. No. 5,356,432 to Rutkow et al. and in revised form by U.S. Pat. No. 5,716,408 to Eldridge et al. This device is in the form of a pleated conical fabric mesh provided with additional mesh filler material within the hollow of the cone; a sheet of material is not attached to the plug. There are reported cases of devices of this type having migrated from the site of the defect. Further, the mesh filler material is often not adequate to provide the necessary axial stiffness and radial compliance to the conical form. These attributes are desirable in order to aid in the insertion of the device into a hernia defect (In the axial direction with regard to the device) and to better enable the device to fill the defect in the radial direction.
U.S. Pat. No. 6,425,924 to Rousseau teaches two opposing conical mesh shapes fitted together on a common axis and separated by one or more tubular components also on the common axis, with the apices of the two cones pointed away from each other. The apex of one cone is affixed to the center of a sheet of mesh material.
Various materials have been discussed for use as prosthetic plugs for the repair of inguinal hernias. Polypropylene and polytetrafluoroethylene are commonly discussed. Polypropylene is most often used in the form of a woven or knitted mesh fabric to create the desired shapes. Polytetrafluoroethylene is typically used in its porous, expanded form, usually noted as ePTFE. Other described non-absorbable materials include cotton, linen, silk, polyamide (e.g., nylon 66) and polyethylene terephthalate. Various absorbable materials have also been proposed, including homopolymers and copolymers of glycolide and lactide, caprolactones and trimethylene carbonates. See, for example, U.S. Pat. No. 6,113,641 to Leroy et al., U.S. Pat. No. 6,180,848 to Flament et al. and U.S. Pat. No. 6,241,768 to Agarwhal et al. While the literature contains suggestions to manufacture hernia repair plugs from absorbable materials, the present inventors are unaware of any such absorbable plugs having ever been made commercially available.
Further, there remains a need for a repair plug that possesses adequate axial stiffness and radial compliance, and encourages rapid healing of the defect.